Excavators for digging trenches and the like

ABSTRACT

An excavator comprising a bucket-carrying arm articulated to a jib has a winch permanently mounted on the jib. The winch carries a lifting tackle-block via a cable entrained over a pulley mounted on the jib or arm.

United States Patent 11 1 1 1 3,874,532 Metailler Apr. 1, 1975 1 EXCAVATORS FOR DIGGING TRENCHES [56] References Cited AND THE LIKE UNITED STATES PATENTS [75] Inventor: Roger Metailler, Grenoble, France 2,801,012 7/1957 Lederer 214/138 R 1 Assignee= some dim RICHIER, Paris, 533253123 11132? 255321131111: ""ijjiiifiliffi France 3,606,048 9/1971 Long 214/138 [22] Filed: June 14, 1972 Alb J M k Primary Examiner ert a ay [21] App! 262,540 Att0rney,Agent, 0r Firm-Eyre, Mann & Lucas [30] Foreign Application Priority Data [57] ABSTRACT June 16. France An ex avator comprising a bucket carrying arm articulated to a jib has a winch permanently mounted on [52] U.S. Cl. 214/138, 212/59 the jib The winch Carries a lifti tackleblock via a [51] Int. Cl E021 3/28 bl entrained ver a pulley mounted on the jib Or [58] Field of Search 214/138, 145, 147 G; arm.

2 Claims, 4 Drawing Figures EXCAVATORS FOR DIGGING TRENCHES AND THE LIKE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to excavators.

2. Description of the Prior Art One previously proposed excavator comprises an arm articulated on a jib which is itself articulated on a pivotal platform. A bucket is articulated on the free end portion of the arm. and can be used for example to dig a trench.

In order to raise or set down a load using this excavator a rope can be attached to the teeth of the bucket or to a lug welded thereon. This solution is very simple, since it requires no conversion of the shovel, but it does prevent simultaneous use of the bucket and, moreover, the raising or lowering of the load is accompanied by a change in the operating radius of the load which it is possible to raise.

Alternatively the bucket and its actuating ram can be removed, a lifting hook being provided in place of the bucket. This arrangement has virtually the same drawbacks as the foregoing and, moreover, the additional disadvantage of requiring partial dismantling of the excavator.

An object of the present invention is to provide an excavator which can also be used as a device for lifting and handling loads without any need to modify the excavator.

SUMMARY OF THE INVENTION The excavator according to the invention incorporates a winch mounted permanently on the jib and connected to a tackle block by a hoisting cable passing over one or a plurality of reversing pulleys, wherein the axis of connection of the jib to the arm and/or the axis of connection of the bucket to the end of the arm and- /or the axis of connection of the bucket to the end of the arm and/or an auxiliary axis carried by the jib or the arm comprise. at one of their extremities at least, an extension capable of receiving the reversing pulley or pulleys. and comprises means for fixing the tackle-block to the jib or to an element rigid therewith whereby to store the tackle-block in an inoperative condition.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described. by way of example only, with reference to the accompanying diagrammatic drawings, in which:

FIG. 1 is an elevation of an excavator in accordance with the invention;

FIG. 2 is a fragmentary plan view of the excavator;

FIG. 3 is an elevation illustrating the manner in which the lowering of a load by means of a jib ram causes the radius of operation of the load to vary; and

FIG. 4 is an end elevation of the excavator.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. I an excavator comprises a chassis I provided with conventional driving means (not shown). A platform 2 is pivotal about an axis x-x on the chassis I through a slewing ring gear 3. Reference numeral 4 denotes a control position from which the driver of the excavator can direct all operations.

A fork 5 is pivotal at 6 on the platform 2 and can be displaced by a hydraulic ram 7. A jib 8, connected to the fork 5 by a shaft 9. is attached to the fork 5 at a seleeted one of a number of positions lOa, 10b, 10(- and 1011. An arm 11 is pivotal at 12 at the outer end portion of the jib 8 and is displacable by means of a ram I3. An excavator bucket 14 is pivotal at I5 at the end portion of the arm 11 and is operated by means of a ram 16.

The excavator can be used to dig trenches 17 by using the bucket 14. If the trench 17 receives piping constituted by juxtaposed elements 18 which may be of relatively considerable size and weight, each element is forced onto the end of the previous element to ensure fluid-tightness of the piping and in certain cases tightness between one element and another.

This particular operation is facilitated by the excavator as will now be described.

A winch 19 is mounted on the jib 8 and has a cable 20 attached to a tackle-block 21, the hook of which is shown at 22. The cable 20 passes over reversing pulleys 23a and 231; which enable a four-strand tackle to be used and which can be mounted either on the pivot 10", on the pivot 12 or on the pivot 15, these pivots being sufficiently extended, at at least one of their ends, to be able to carry these pulleys, as shown diagrammatically in FIG. 2. A ring 24 mounted on the fork 5 enables the tackle-block 21 to be attached thereto while the excavator is being used to dig a trench.

If the reversing pulleys 23a and 23b are mounted on the pivot 15, in order to prevent hoisting movements from being hampered, the bucket 14 is raised to its maximum height by retracting the ram 15 to its fullest extent.

The pulleys 23a and 23h can be placed on one side of the pivots 10c, 12 or 15. It is then possible to modify the radius of operation of the hook 22 of the tackleblock by changing the angle of inclination of the fork 25, by means of the ram 7. It will be observed that the raising of a load, for example an element 18, by means of the tackle-block 21 and its winch 19 is performed with no change in span, therefore with no variation in the conditions of stability. On the contrary, the lowering of a load by the operation of one of the rams 7, 13 or 16 would result in a considerable variation in span, and consequently the centre of gravity, and the possibility of the excavator tipping over would be increased. It will thus be seen that the excavator described can lift heavy loads and maintain a constant radius of operation of these loads whilst permitting a considerable lifting height.

It is possible to locate the two pulleys 23a and 23b on either side of the arm 11 or of the jib 9. In this case, the tackle block 21 is located in the median longitudinal plane of the excavator as shown in FIG. 4. Under these conditions, the elements 18 can be fitted into one another, using the ram 16 and a sling 25, the hooks of which are secured to the bucket 14 and to the element 18 (FIG. 1).

What is claimed is:

1. In an excavator,

a jib member,

a pivotal platform,

first pivot means for articulating said jib to said platform,

an arm member,

second pivot means for articulating the arm member to the jib member at one end thereof,

a bucket,

third pivot means for articulating the bucket to the arm member at one end thereof,

a winch mounted permanently on the jib member.

a tackle-block,

hoisting cable means,

at least one pulley, the winch being connected to the tackle-block by the hoisting cable means which passes over the pulley,

means for mounting the pulley exterior to one of said members positioned to permit unobstructed movement of said tackle-block,

means for retaining the tackle-block in a stored condition, and

wherein said arm member has at least one auxiliary axis transverse therewith intermediate the ends thereof and wherein said pulley mounting means comprise an extension positioned coaxial with said at least one auxiliary axis.

2. In an excavator,

a jib member,

a pivotal platform,

first pivot means for articulating said jib to said platform,

an arm member,

second pivot means for articulating the arm member to the jib member at one end thereof,

a bucket,

third pivot means for articulating the bucket to the arm member at one end thereof,

a winch mounted permanently on the jib member,

a tackle-block,

hoisting cable means,

at least one pulley, the winch being connected to the tackle-block by the hoisting cable means which passes over the pulley, I

means for mounting the pulley exterior to one of said members positioned to permit unobstructed movement of said tackle-block,

means for retaining the tackle-block in a stored condition, and

wherein said jib member has at least one auxiliary axis transverse therewith intermediate the ends thereof and wherein said pulley mounting means comprise an extension positioned coaxial with said at least one auxiliary axis. 

1. In an excavator, a jib member, a pivotal platform, first pivot means for articulating said jib to said platform, an arm member, second pivot means for articulating the arm member to the jib member at one end thereof, a bucket, third pivot means for articulating the bucket to the arm member at one end thereof, a winch mounted permanently on the jib member, a tackle-block, hoisting cable means, at least one pulley, the winch being connected to the tackleblock by the hoisting cable means which passes over the pulley, means for mounting the pulley exterior to one of said members positioned to permit unobstructed movement of said tackleblock, means for retaining the tackle-block in a stored condition, and wherein said arm member has at least one auxiliary axis transverse therewith intermediate the ends thereof and wherein said pulley mounting means comprise an extension positioned coaxial with said at least one auxiliary axis.
 2. In an excavator, a jib member, a pivotal platform, first pivot means for articulating said jib to said platform, an arm member, second pivot means for articulating the arm member to the jib member at one end thereoF, a bucket, third pivot means for articulating the bucket to the arm member at one end thereof, a winch mounted permanently on the jib member, a tackle-block, hoisting cable means, at least one pulley, the winch being connected to the tackle-block by the hoisting cable means which passes over the pulley, means for mounting the pulley exterior to one of said members positioned to permit unobstructed movement of said tackle-block, means for retaining the tackle-block in a stored condition, and wherein said jib member has at least one auxiliary axis transverse therewith intermediate the ends thereof and wherein said pulley mounting means comprise an extension positioned coaxial with said at least one auxiliary axis. 